In recent years, semiconductor integrated circuit devices (IC chips) used as microprocessors of computers or the like have greatly advanced in operation speed and functionality. In association with such advancement, the number of terminals tends to increase, and the pitch of terminals tends to become narrower. Generally, a large number of terminals are densely arranged in an array on the bottom surface of an IC chip. Such a group of terminals are flip-chip-connected to a group of terminals on a motherboard. However, since there is a great difference in the pitch of terminals between the group of terminals on the IC chip and the group of terminals on the motherboard, difficulty is encountered in connecting the IC chip directly onto the motherboard. Thus, usually, the IC chip is mounted on a wiring substrate, thereby yielding a package. Then, the package is mounted on the motherboard. In order to reduce noise of the IC chip and to stabilize a power supply voltage, incorporation of a capacitor is conventionally proposed for a wiring substrate used to form a package of such a type (refer to, for example, Patent Documents 1 and 2).
Examples of a capacitor to be incorporated in the above-mentioned wiring substrate include a via-array-type capacitor and a sheet capacitor. The via-array-type capacitor includes a capacitor body having a structure in which internal electrode layers are arranged in layers with individual dielectric layers intervening therebetween, and a plurality of via conductors for establishing electrical communication among the internal electrode layers. The via conductors are arranged in an array. The sheet capacitor has a structure of lamination of an electrode layer and a dielectric layer. In the case of incorporation of a via-array-type capacitor in a wiring substrate, the capacitor makes it easier to achieve high capacitance with a small size and enables stable power supply.
Meanwhile, an IC chip has a processor core (arithmetic processing section) provided therein. Since, in addition to the processor core, various circuit sections; for example, an I/O circuit section and a memory, are provided in the IC chip, individual power supply systems must be set for these circuit sections in future. Thus, in this case, even though a via-array-type capacitor is incorporated in a wiring substrate, the processor core and various circuit sections cannot be operated sufficiently. Accordingly, conceivably, the IC chip fails to exhibit its maximum capability, resulting in a failure to achieve high functionality. In order to cope with this situation, conventionally, there is proposed a package in which a capacitor 411 is incorporated in a wiring substrate 401, and chip capacitors 412 are mounted on a front surface 402 or back surface 403 of the wiring substrate 401 (for example, see FIG. 16). By virtue of the capacitor 411 and the chip capacitors 412, a processor core and various circuit sections provided in an IC chip 413 can be operated sufficiently. Accordingly, the IC chip 413 can exhibit its maximum capability, whereby high functionality becomes easy to achieve.